Selected Aspects of the Octupole Degree of Freedom
Seminars
Seminar “Nuclear Theory”
Date and Time: Monday, 13 August 2018, at 3:30 PM
Venue: Lecture Hall (2nd floor), Bogoliubov Laboratory of Theoretical Physics
Seminar topic: «Selected Aspects of the Octupole Degree of Freedom»
Speaker: Marcus Scheck (University of the West of Scotland)
Abstract
The talk will introduce the physics of strongly octupole correlated nuclei and the related observable. The experimental technique of Coulomb excitation, which is the standard method to measure E3 excitation strength is elucidated and results from a previous campaign at REX-ISOLDE (CERN) are presented. Furthermore, a new technique to measure E3 transition strength based on the observation of weak γ-ray branches employing modern highly-efficient detector arrays is introduced. The REX-ISOLDE results highlight the relation between quadrupole-octupole coupling and an intrinsic electric dipole moment, which in the laboratory frame results in a CP-violating Schiff moment. For the octupole correlated odd-mass nuclei characteristic parity doublets are explained and the idea of Mössbauer spectroscopy to measure the Schiff moment in the Jπ = 3/2± parity doublet of 227Ac is presented. The talk will conclude with a short summary about very recent Coulomb-excitation measurements in the A ≈ 144 and A ≈ 224 mass regions at HIE-ISOLDE (CERN) and an outlook about future experimental activities is provided.